/*header*/
.header{
    background-color: rgba(24,40,66,0.1);
    position: fixed;
    width: 100%;
    z-index: 3;
}
.header__wrap{
    width: 100%;
    height: 80px;
    position: relative;

}
.header__logo{
    background: url("../img/logo.png")left center no-repeat;
    width: 160px;
    height: 40px;
    background-size: 40px 40px;
    position: absolute;
    font-size: 20px;
    font-weight: bolder;
    color: #fff;
    text-indent: 50px;
    /*text-indent文字缩进距离为logo图片加文字大小*/
    line-height: 40px;
    top: 50%;
    margin-top: -20px;
    left: 20px;
}

.header__nav{
    position: absolute;
    height: 40px;
    right: 30px;
    top: 50%;
    margin-top: -20px;
}
.header__nav__item{
    color: #fff;
    display: block;
    position: relative;
    padding-left: 40px;
    height: 40px;
    font-size: 12px;
    line-height: 40px;
    float: left;
}

.header__nav__item:hover{
    color: #f01400;
}
/*.header__nav__item__status__active::after{*/
    /*content: '  ';*/
    /*display: block;*/
    /*width: 100%;*/
    /*height: 2px;*/
    /*position: absolute;*/
    /*background-color: #f01400;*/
    /*left: 0;*/
    /*bottom:0;*/
/*}*/
.header__nav__item--study-now{
    background: #f00;
    text-align: center;
    width: 94px;
    border-radius: 3px;
    padding: 0;
    margin-left: 40px;
}
.header__nav__item--study-now:hover{
    box-shadow:0px 0px 10px #f06;
    transition: all .5s;
    color: white;
}

.header_nav_tip{
    width: 48px;
    height: 2px;
    position: absolute;
    background-color: #f00;
    bottom: 0;
    left: 0;
    transition: all .5s;
    margin-left: 40px;
}

/*container*/
.container{
    width: 1200px;
    height: 640px;
}

/*screen-1*/
.screen-1{
    height: 640px;
    margin: 0 auto;
    color: #fff;
    position: relative;

}
.screen-1__practice-courses{
    background: url("../img/sc1.jpg")no-repeat center;
    height: 640px;
    background-size: cover;
}
.screen-1__heading{
    position: absolute;
    width: 456px;
    font-size: 38px;
    top: 240px;
    left: 50%;
    margin-left: -168px;

}
.screen-1__heading-descrip{
    position: absolute;
    z-index: 1;
    width: 336px;
    left: 50%;
    margin-left: -168px;
    text-align: center;
    top: 318px;
}

/*screen-2*/
.screen-2{
    width: 1200px;
    height: 640px;
    margin: 0 auto;
    position: relative;
}
.screen-2__heading{
    font-size: 40px;
    line-height: 40px;
    margin-left: 0;
    padding: 0;
    text-align: center;
    margin-top: 90px;
}
.screen-2__sub-heading-tip{
    height: 3px;
    width: 54px;
    background: #f00;
    margin: 32px auto;
}
.screen-2__sub-heading{
    margin: 22px auto;
    padding: 0;
    text-align: center;
}
.screen-2__banner{
    position: relative;
}
.screen-2__banner_i_1{
    background-image: url("../img/sc2.png");
    width: 750px;
    height: 360px;
    position: absolute;
    left: 50%;
    margin-left: -375px;
    margin-top: 110px;
}
.screen-2__banner_i_2{
    background: url("../img/sc2-1.png")center no-repeat;
    width: 275px;
    height: 380px;
    position: absolute;
    left: 50%;
    margin-left: -137px;
    z-index: 2;
    margin-top: 90px;
}
.screen-2__banner_i_3{
    background-image: url("../img/sc2-2.png");
    width: 266px;
    height: 204px;
    position: absolute;
    right: 370px;
    top: 166px;
    z-index: 1;
}

/*screen-3*/
.screen-3{
    height: 640px;
    background-color: #2b333b;
    position: relative;
}
.screen-3__icon{
    background: url("../img/sc3.png")no-repeat center;
    height: 632px;
    width: 570px;
    position: relative;
    margin-left: 120px;
    z-index: 2;
    background-size: cover;
    float: left;
}
.screen-3__content{
    width: 630px;
    height: 640px;
    float: left;
}
.screen-3__content__heading{
    float: left;
    font-size: 36px;
    margin-left: 200px;
    width: 396px;
    margin-top: 230px;
    color: #fff;
}
.screen-3__content__tip{
    height: 2px;
    width: 50px;
    margin-left: 200px;
    background-color: #f01400;
    position: absolute;
    top: 294px;
}
.screen-3__content__subheading{
    color: white;
    position: absolute;
    top: 324px;
    margin-left: 200px;
    font-size: 14px;
    width: 512px;
}
.screen-3__content__items{
    position: absolute;
    margin-top: 456px;
    margin-left: 200px;
    height: 72px;
    width: 512px;
    line-height: 72px;

    /*呼吸灯效果*/
    /* IE10、Firefox and Opera，IE9以及更早的版本不支持 */
    animation-name: breath;                         /* 动画名称 */
    animation-duration: 3s;                         /* 动画时长3秒 */
    animation-timing-function: linear;         /* 动画速度曲线：以低速开始和结束 */
    animation-iteration-count: 3;            /* 播放次数：无限 */

    /* Safari and Chrome */
    -webkit-animation-name: breath;                 /* 动画名称 */
    -webkit-animation-duration: 2s;                 /* 动画时长3秒 */
    -webkit-animation-timing-function: linear; /* 动画速度曲线：以低速开始和结束 */
    -webkit-animation-iteration-count: 2;    /* 播放次数：无限 */
}
@keyframes breath {
    from { opacity: 0.1; }                          /* 动画开始时的不透明度 */
    50%  { opacity:   0.5; }                          /* 动画50% 时的不透明度 */
    to   { opacity: 1; }                          /* 动画结束时的不透明度 */
}

@-webkit-keyframes breath {
    from { opacity: 0.1; }                          /* 动画开始时的不透明度 */
    50%  { opacity:   0.5; }                          /* 动画50% 时的不透明度 */
    to   { opacity: 1; }                          /* 动画结束时的不透明度 */
}
.screen-3__content__items-1{
    color: #2294ff;
    border-radius: 50%;
    border: 4px solid #1f5975 ;
    height: 74px;
    width: 74px;
    display: inline-block;
    text-align: center;
    margin-right: 14px;
}
.screen-3__content__items-2{
    color: #7888fd;
    border-radius: 50%;
    border: 4px solid #7888fd ;
    height: 74px;
    width: 74px;
    display: inline-block;
    text-align: center;
    margin-right: 14px;
}
.screen-3__content__items-3{
    color: #ff6060;
    border-radius: 50%;
    border: 4px solid #6b4146 ;
    height: 74px;
    width: 74px;
    display: inline-block;
    text-align: center;
    margin-right: 14px;
}
.screen-3__content__items-4{
    color: #25c7e5;
    border-radius: 50%;
    border: 4px solid #29535f ;
    height: 74px;
    width: 74px;
    display: inline-block;
    text-align: center;
    margin-right: 14px;
}
.screen-3__content__items-5{
    color: #90bd4b;
    border-radius: 50%;
    border: 4px solid #3e4e40 ;
    height: 74px;
    width: 74px;
    display: inline-block;
    text-align: center;
    margin-right: 14px;
}

/*screen-4*/
.screen-4{
    background-color: #f5f3f7;
    height: 640px;
}
.screen-4__heading{
    font-size: 42px;
    text-align: center;
    padding-top: 89px;
}
.screen-4__tips{
    height: 2px;
    width: 50px;
    margin: 0 auto;
    background-color: #f01400;
    margin-top: 33px;
}
.screen-4__subheading{
    width: 1200px;
    font-size: 18px;
    margin-top: 30px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

.screen-4__items{
    margin: 80px auto;
    width: 1200px;
    height: 300px;
}

.screen-4__items-wrap1,
.screen-4__items-wrap2,
.screen-4__items-wrap3,
.screen-4__items-wrap4{
    width: 300px;
    height: 400px;
    float: left;
    text-align: center;
}

.screen-4__items-1-icon{
     background: url("../img/sc4-1.png")no-repeat center;
     height: 72px;
     margin-bottom: 24px;
}

.screen-4__items-2-icon{
    background: url("../img/sc4-2.png")no-repeat center;
    height: 72px;
    margin-bottom: 24px;
}

.screen-4__items-3-icon{
    background: url("../img/sc4-3.png")no-repeat center;
    height: 72px;
    margin-bottom: 24px;
}

.screen-4__items-4-icon{
    background: url("../img/sc4-4.png")no-repeat center;
    height: 72px;
    margin-bottom: 24px;
}




/*screen-5*/
.screen-5{
    width:100%;
    height: 640px;
    background-image: url("../img/sc5.jpg");
    background-size: cover;
    position: relative;
}
.screen-5_icon{
    background-image: url("../img/sc5-1.png");
    width: 200px;
    height: 200px;
    top: 98px;
    position: absolute;
    left: 50%;
    margin-left: -100px;
}
.screen-5_heading{
    position: absolute;
    font-size: 40px;
    color: white;
    top:358px;
    left: 50%;
    margin-left: -300px;
}
.screen-5_tip{
    height: 2px;
    width: 50px;
    left: 50%;
    margin-left: -25px;
    background-color: #fff;
    position: absolute;
    top: 460px;
}
.screen-5_subheading{
    font-size: 16px;
    color: #fff;
    position: absolute;
    top: 480px;
    left: 50%;
    margin-left: -344px;
}

/*others*/
.screen-others{
    background-color: #fff;
    height: 200px;
    overflow: hidden;
}
.screen-others_btn{
    display: block;
    border: 1px solid #707070;
    width: 238px;
    height: 56px;
    margin-top: 70px;
    margin-left: auto;
    margin-right: auto;
    line-height: 56px;
    text-align: center;
    border-radius: 3px;
    color: black;
}
.screen-others_btn:hover{
    box-shadow:0px 0px 10px rgba(0,0,0,0.5);
    /*给即刻学习体验按钮添加环绕四周阴影,形如'0px 0px 10px',如果0px有值则为按钮有下侧有效果*/
    transition: all .5s;
    /*按钮过渡渐变动画*/
    color: #717171;
}

/*footer*/
.footer{
    background-color: #000;
    height: 108px;
    position: relative;

}
.footer_link{
    position: absolute;
    top: 30px;
    margin-left: 50%;
    left: -348px;
    color: #8fc0c4;
}
.footer_link a{
    color: white;
    margin-right:36px;
    font-size: 12px;
}
.footer_link a:hover{
    color: #f01400;
}
.footer p{
    color: white;
    position: absolute;
    top: 60px;
    font-size: 14px;
    color: #787d82;
    left: 50%;
    margin-left: -244px;
}

/*outline*/
.outline{
    width: 90px;
    height: 180px;
    bottom: 120px;
    box-shadow: 0px 4px 12px 0px rgba(7, 17, 27, 0.1);
    /*outline阴影*/
    border-radius: 3px;
    position: fixed;
    right: 0;
    background-color: white;
}
.outline__nav{
    text-align: center;
    display: block;
    height: 30px;
    line-height: 30px;
    font-size: 15px;
    color: black;

}
.outline__nav:hover{
    color: #f01400;
}

*{margin:0;padding:0;}
a{text-decoration: none;}
body{background-color: #F2F4F6;}

/*header animation*/
.header{
    transition: all 1s;
}
.header_status_white{
    background-color: rgba(255,255,255,.9);
    top: 0;
    right: 0;
    left: 0;
}
.header_status_white .header__nav__item,
.header_status_white .header__logo{
    color: #000;
}

.header_status_white .header__nav__item__status__active{
    color: #f01400;
}

.header__nav__item__status__active{
    color: #f01400;
}

.header_status_white .header__nav__item:hover{
    transition: all 1s;
    color: red;
}
.header_status_white .header__nav__item--study-now:hover{
    color: #fff;
}

/*screen-1 animation*/
.screen-1__heading{
    transition: all 1s .5s;
}
.screen-1__heading_animate_init{
    opacity: 0;
    transform: translate(0,-100%);
}

.screen-1__heading_animate_done{
    opacity: 1;
    transform: translate(0,0);
}

.screen-1__heading-descrip{
    transition: all 1s 1s;
}

.screen-1__heading-descrip_animate_init{
    opacity: 0;
    transform: translate(0,100%);
}

.screen-1__heading-descrip_animate_done{
    opacity: 1;
    transform: translate(0,0);
}



/*screen-2 animation*/
/*顺序:大标题-->次级标题和线条-->人-->火箭*/

.screen-2__heading{
    transition: all 1s 0.5s;
}
.screen-2__sub-heading-tip{
    transition: all 1s 1s;
}
.screen-2__sub-heading{
    transition: all 1s 1.2s;
}
.screen-2__banner_i_2{
    transition: all 1s 1.5s;
}
.screen-2__banner_i_3{
    transition: all 1s 2s;
}


.screen-2__heading_animate_init,
.screen-2__sub-heading-tip_animate_init,
.screen-2__sub-heading_animate_init,
.screen-2__banner_i_2_animate_init,
.screen-2__banner_i_3_animate_init{
    opacity: 0;
    transform: translate(0,100%);
}

.screen-2__heading_animate_done,
.screen-2__sub-heading-tip_animate_done,
.screen-2__sub-heading_animate_done,
.screen-2__banner_i_2_animate_done,
.screen-2__banner_i_3_animate_done{
    opacity: 1;
    transform: translate(0,0);
}

/*screen-3 animation*/
/*顺序:原子图(从小到大地放大)-->一级标题-->横线-->二级标题-->5个圆环*/

.screen-3__icon{
    transition: all 1s ;
}
.screen-3__content__heading{
    transition: all 1s 0.5s;
}
.screen-3__content__tip{
    transition: all 1s 0.5s;
}
.screen-3__content__subheading{
    transition: all 1s 0.5s;
}
.screen-3__content__items{
    transition: all 1s 1s;
}

.screen-3__icon_animate_init{
    opacity: 0;
    transform: scale(.5);
    /*放大渐变动画:初始'transform: scale(.5);'*/
}
.screen-3__content__heading_animate_init,
.screen-3__content__tip_animate_init,
.screen-3__content__subheading_animate_init,
.screen-3__content__items_animate_init{
    opacity: 0;
    transform: translate(0,100%);
}

.screen-3__icon_animate_done{
    opacity: 1;
    transform: scale(1);
    /*放大渐变动画:完成'transform: scale(1);'*/
}
.screen-3__content__heading_animate_done,
.screen-3__content__tip_animate_done,
.screen-3__content__subheading_animate_done,
.screen-3__content__items_animate_done{
    opacity: 1;
    transform: translate(0,0);
}

/*screen4 animation*/
/*x顺序:标题一级-->横线-->标题二级-->图例弹出*/
.screen-4__heading{
    transition: all 1s ;
}
.screen-4__tips{
    transition: all 1s 1s;
}
.screen-4__subheading{
    transition: all 1s 1s;
}
.screen-4__items-wrap1,
.screen-4__items-wrap2,
.screen-4__items-wrap3,
.screen-4__items-wrap4{
    transition: all 1s ;
}

.screen-4__heading_animate_init,
.screen-4__tips_animate_init,
.screen-4__subheading_animate_init{
    opacity: 0;
    transform: translate(0,100%);
}

.screen-4__items-wrap1_animate_init,
.screen-4__items-wrap2_animate_init,
.screen-4__items-wrap3_animate_init,
.screen-4__items-wrap4_animate_init{
    opacity: 0;
    transform: scale(.5);
}


.screen-4__heading_animate_done,
.screen-4__tips_animate_done,
.screen-4__subheading_animate_done{
    opacity: 1;
    transform: translate(0,0);
}

.screen-4__items-wrap1_animate_done,
.screen-4__items-wrap2_animate_done,
.screen-4__items-wrap3_animate_done,
.screen-4__items-wrap4_animate_done{
    opacity: 1;
    transform: scale(1);
}


/*screen5 animation*/
/*顺序:头像放大弹出-->标题顺序展示*/
.screen-5_icon{
    transition: all 1s;
}
.screen-5_heading{
    transition: all 1s 0.5s;
}
.screen-5_tip{
    transition: all 1s 1s;
}
.screen-5_subheading{
    transition: all 1s 1.2s;
}

.screen-5_icon_animate_init{
    opacity: 0;
    transform: scale(0.5);
}
.screen-5_heading_animate_init,
.screen-5_tip_animate_init,
.screen-5_subheading_animate_init{
    opacity: 0;
    transform: translate(0,100%);
}

.screen-5_icon_animate_done{
    opacity: 1;
    transform: scale(1);
}
.screen-5_heading_animate_done,
.screen-5_tip_animate_done,
.screen-5_subheading_animate_done{
    opacity: 1;
    transform: translate(0,0);
}

/*outline*/
.outline{
    opacity: 0;
    transform: translate(100%,0);
    transition: all 1s;
}
.outline_status_in{
    opacity: 1;
    transform: translate(0,0);
}
.outline__item{
    transition: all 1s;
}

.outline__nav__status__active{
    color: #f01400;
}





